title: Multifocal visual evoked potential in optic neuritis, ischemic optic neuropathy and compressive optic neuropathy.
abstract: OBJECTIVE
  To investigate the effect of optic neuritis (ON), ischemic optic neuropathy (ION) and compressive optic neuropathy (CON) on multifocal visual evoked potential (mfVEP) amplitudes and latencies, and to compare the parameters among three optic nerve disorders.
  
  
  METHODS
  mfVEP was recorded for 71 eyes of controls and 48 eyes of optic nerve disorders with subgroups of optic neuritis (ON, n = 21 eyes), ischemic optic neuropathy (ION, n = 14 eyes), and compressive optic neuropathy (CON, n = 13 eyes). The size of defect in mfVEP amplitude probability plots and relative latency plots were analyzed. The pattern of the defect in amplitude probability plot was classified according to the visual field profile of optic neuritis treatment trail (ONTT).
  
  
  RESULTS
  Median of mfVEP amplitude (log SNR) averaged across 60 sectors were reduced in ON (0.17 (0.13-0.33)), ION (0.14 (0.12-0.21)) and CON (0.21 (0.14-0.30)) when compared to controls. The median mfVEP relative latencies compared to controls were significantly prolonged in ON and CON group of 10.53 (2.62-15.50) ms and 5.73 (2.67-14.14) ms respectively compared to ION group (2.06 (-4.09-13.02)). The common mfVEP amplitude defects observed in probability plots were diffuse pattern in ON, inferior altitudinal defect in ION and temporal hemianopia in CON eyes.
  
  
  CONCLUSIONS
  Optic nerve disorders cause reduction in mfVEP amplitudes. The extent of delayed latency noted in ischemic optic neuropathy was significantly lesser compared to subjects with optic neuritis and compressive optic neuropathy. mfVEP amplitudes can be used to objectively assess the topography of the visual field defect.
authors.forename: Manju
authors.initials: M
authors.lastname: Jayaraman
authors.forename: Rashmin Anilkumar
authors.initials: RA
authors.lastname: Gandhi
authors.forename: Priya
authors.initials: P
authors.lastname: Ravi
authors.affiliation: Department of Vitreoretina Consultant, Sankara Nethralaya, 18 College Road, Chennai, India.
authors.forename: Parveen
authors.initials: P
authors.lastname: Sen
mesh_terms: D000328:Adult; D005074:Evoked Potentials, Visual / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009408:Nerve Compression Syndromes / Q000503:physiopathology*; D009900:Optic Nerve; D009902:Optic Neuritis / Q000503:physiopathology*; D018917:Optic Neuropathy, Ischemic / Q000503:physiopathology*; D012189:Retrospective Studies; D058609:Visual Field Tests; D014794:Visual Fields / Q000502:physiology; D055815:Young Adult